Bias-free Parameter Identification of a Fractional Order Model

This paper deals with the parameter identification of a fractional system considering a noisy observation of the output signal. The novelty is that the instrumental variable method is applied to the modulating function method applied to a fractional system. A simulated output signal which is not correlated to noise is required as the instrumental variable. Because all known simulation algorithms only consider zero initial conditions, the simulated output signal converges against the true output signal in an undefined time if the zero initial conditions are penalized. Therefore, an algorithm is extended with the short-memory principle. The benefit is that after a fixed time the error between the simulated and true output signal is small and can be used as the instrumental variable. Considering this extension of the simulation algorithms, it is shown that a consistent estimation is yield with the instrumental variable method

Securing African forests for future drier climates : applying ecophysiology in tree improvement

Increasing incidences of drought-induced tree mortality are being recorded worldwide, including Africa. African forests cover a significant proportion of the continent, which implies that African forest sustainability is threatened from a climate change perspective. This is especially problematic in a developing nation context, since forest ecosystems such as plantation forestry provide important goods and services that sustain human well-being and economic growth. Disentangling the likely triggers of tree mortality (including those linked to drought) in landscapes would not only explain the mechanisms underlying local die-offs, but also better predict future mortality events. Methods applied in the field of ecophysiology are particularly useful to study in situ plant responses to an environment. We consider the status quo of global peer-reviewed publication outputs during the past century that have made use of key ecophysiological research approaches, specifically studies concerning ‘tree xylem anatomy’, ‘tree xylem cavitation’, ‘tree leaf gas-exchange’, ‘tree xylem hydraulic conductivity’. We highlight the growth and applicability of this research field in understanding tree ecology. We also assess the role that the forestry sector has had in promoting such research to ensure future-proof forest products. Most importantly we consider how Africa with its vast forested landscapes fits within this research spectrum. The last decade saw an increase of up to 60% in the total number of articles published, particularly with a focus on tree xylem cavitation and conductivity. While forest research contributed greatly to the global tally of ecophysiological studies, and such studies in Africa have also increased by up to 88% the past decade, there remains a general lack of this research topic in the continent. It is clear an optimisation of applied ecophysiological concepts and techniques will promote an improved understanding of tree mortality patterns. And we argue that ecophysiological data will be crucial to future-proof tree improvement strategies in African commodity production landscapes, especially given future drier climates.The Tree Protection Co-operative Programme (TPCP) and the Department of Science and Technology (DST)-National Research Foundation (NRF) Centre of Excellence in Tree Health Biotechnology at the University of Pretoria.http://www.tandfonline.com/loi/tsfs202017-08-31hb2017Forestry and Agricultural Biotechnology Institute (FABI)Plant Production and Soil Scienc

Aeolianite and barrier dune construction spanning the last two glacial-interglacial cycles from the southern Cape coast, South Africa

The southern Cape region of South Africa has extensive coastal aeolianites and barrier dunes. Whilst previously reported, limited knowledge of their age has precluded an understanding of their relationship with the climatic and sea-level fluctuations that have taken place during the Late Quaternary. Sedimentological and geomorphological studies combined with an optical dating programme reveal aeolianite development and barrier dune construction spanning at least the last two glacial–interglacial cycles. Aeolianite deposition has occurred on the southern Cape coast at ca 67–80, 88–90, 104–128, 160–189 and >200 ka before the present. Using this and other published data coupled with a better understanding of Late Quaternary sea-level fluctuations and palaeocoastline configurations, it is concluded that these depositional phases appear to be controlled by interglacial and subsequent interstadial sea-level high stands. These marine transgressions and regressions allowed onshore carbonate-rich sediment movement and subsequent aeolian reworking to occur at similar points in the landscape on a number of occasions. The lack of carbonates in more recent dunes (Oxygen Isotope Stages 1/2 and 4/5) is attributed not to leaching but to changes to carbonate production in the sediment source area caused by increased terrigenous material and/or changes in the balance between the warm Agulhas and nutrient-rich Benguela ocean current

PArallel, Robust, Interface Simulator (PARIS)

Paris (PArallel, Robust, Interface Simulator) is a finite volume code for simulations of immiscible multifluid or multiphase flows. It is based on the "one-fluid" formulation of the Navier-Stokes equations where different fluids are treated as one material with variable properties, and surface tension is added as a singular interface force. The fluid equations are solved on a regular structured staggered grid using an explicit projection method with a first-order or second-order time integration scheme. The interface separating the different fluids is tracked by a Front-Tracking (FT) method, where the interface is represented by connected marker points, or by a Volume-of-Fluid (VOF) method, where the marker function is advected directly on the fixed grid. Paris is written in Fortran95/2002 and parallelized using MPI and domain decomposition. It is based on several earlier FT or VOF codes such as Ftc3D, Surfer or Gerris. These codes and similar ones, as well as Paris, have been used to simulate a wide range of multifluid and multiphase flows

Search Engine Advertising: Channel Substitution when Pricing Ads to Context

We explore substitution patterns across advertising platforms. Using data on the advertising prices paid by lawyers for 139 Google search terms in 195 locations, we exploit a natural experiment in “ambulance-chaser” regulations across states. When lawyers cannot contact clients by mail, advertising prices per click for search engine advertisements are 5%–7% higher. Therefore, online advertising substitutes for offline advertising. This substitution toward online advertising is strongest in markets with fewer customers, suggesting that the relationship between the online and offline media is mediated by the marketers' need to target their communications.NET Institut

Complementâ induced activation of the cardiac NLRP3 inflammasome in sepsis

Cardiac dysfunction develops during sepsis in humans and rodents. In the model of polymicrobial sepsis induced by cecal ligation and puncture (CLP), we investigated the role of the NLRP3 inflammasome in the heart. Mouse heart homogenates from shamâ procedure mice contained high mRNA levels of NLRP3 and ILâ 1β. Usingthe inflamm a some protocol, exposure of cardiomyocytes (CMs) to LPS followed by ATP or nigericin caused release of mature ILâ 1β. Immuno staining of left ventricular frozen sections before and 8 h after CLP revealed the presence of NLRP3 and ILâ 1β proteins inCMs. CLP caused substantial increases in mRNAs for ILâ 1β and NLRP3 in CMs which are reduced in the absence of either C5aR1 or C5aR2. After CLP, NLRP32/2 mice showed reduced plasma levels of ILâ 1βand ILâ 6. In vitro exposure of wildâ type CMs to recombinant C5a (rC5a) cause delevations in both cytosolic and nuclear/mitochondrial reactive oxygen species (ROS), which were C5aâ receptor dependent. Use of a selective NOX2 inhibitor prevented increased cytosolic and nuclear/mitochondrial ROS levels and release of ILâ 1β. Finally, NLRP32/2 mice had reduced defects in echo/Doppler parameters in heart afterCLP. These studies establish that the NLRP3 inflammasome contributes to the cardiomyopathy of polymicrobial sepsis.â Kalbitz, M., Fattahi, F., Grailer, J. J., Jajou, L., Malan, E. A., Zetoune, F. S., Huberâ Lang, M., Russell, M. W., Ward, P. A. Complementâ induced activation of the cardiac NLRP3 inflammasome in sepsis. FASEB J. 30, 3997â 4006 (2016). www.fasebj.orgPeer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154362/1/fsb2fasebj30120728r.pd

Systemic cost of risk for heavy haul operations in South Africa

Abstract: This paper compares the systemic cost of risk between the two heavy haul lines and general freight routes on the South African rail network to determine operational resilience of heavy haul rail systems in a growing export market. The Railway Safety Regulator in South Africa requires permitted railway operators to report extrinsic incidents and intrinsic occurrences in a standardised manner, as well as direct costs aggregated for combined categories. Data recorded and categorized since 2009 according to national standards provides insight into route-specific systemic cost of risk when related to the gross domestic product railed over time. The 33,079 intrinsic occurrences and extrinsic incidents were geospatially superimposed to the nearest station on an existing audited rail freight flow model for South Africa. Reported railway occurrence cost was allocated on an average basis to the nearest station associated with an incident or occurrence. A leading business intelligence tool was used to query the combined database. Data was visualized using maps, animations and graphs. Results suggest that over time the heavy haul remote western iron ore export line exhibits superior route-specific systemic cost of risk when compared to the more populous coal export line over difficult terrain in the east, and the various general freight lines. Evidence suggests that, in terms of systemic cost of risk, the heavy haul model is resilient in a growing market. The paper concludes that socioeconomic factors, topography, and railway operational considerations contribute to systemic cost of risk

Novel Bone-Targeting Agent for Enhanced Delivery of Vancomycin to Bone

We examined the pharmacokinetic properties of vancomycin conjugated to a bone-targeting agent (BT) with high affinity for hydroxyapatite after systemic intravenous administration. The results confirm enhanced persistence of BT-vancomycin in plasma and enhanced accumulation in bone relative to vancomycin. This suggests that BT-vancomycin may be a potential carrier for the systemic targeted delivery of vancomycin in the treatment of bone infections, potentially reducing the reliance on surgical debridement to achieve the desired therapeutic outcome